From 8d34c993a9a156e657e43cb95186980745cc3597 Mon Sep 17 00:00:00 2001 From: Carlos Llamas Date: Tue, 10 Feb 2026 23:28:20 +0000 Subject: rust_binder: fix oneway spam detection commit 4fc87c240b8f30e22b7ebaae29d57105589e1c0b upstream. The spam detection logic in TreeRange was executed before the current request was inserted into the tree. So the new request was not being factored in the spam calculation. Fix this by moving the logic after the new range has been inserted. Also, the detection logic for ArrayRange was missing altogether which meant large spamming transactions could get away without being detected. Fix this by implementing an equivalent low_oneway_space() in ArrayRange. Note that I looked into centralizing this logic in RangeAllocator but iterating through 'state' and 'size' got a bit too complicated (for me) and I abandoned this effort. Cc: stable Cc: Alice Ryhl Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Signed-off-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260210232949.3770644-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder/range_alloc/tree.rs | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/android/binder/range_alloc/tree.rs') diff --git a/drivers/android/binder/range_alloc/tree.rs b/drivers/android/binder/range_alloc/tree.rs index 838fdd2b47ea..48796fcdb362 100644 --- a/drivers/android/binder/range_alloc/tree.rs +++ b/drivers/android/binder/range_alloc/tree.rs @@ -164,15 +164,6 @@ impl TreeRangeAllocator { self.free_oneway_space }; - // Start detecting spammers once we have less than 20% - // of async space left (which is less than 10% of total - // buffer size). - // - // (This will short-circut, so `low_oneway_space` is - // only called when necessary.) - let oneway_spam_detected = - is_oneway && new_oneway_space < self.size / 10 && self.low_oneway_space(pid); - let (found_size, found_off, tree_node, free_tree_node) = match self.find_best_match(size) { None => { pr_warn!("ENOSPC from range_alloc.reserve_new - size: {}", size); @@ -203,6 +194,15 @@ impl TreeRangeAllocator { self.free_tree.insert(free_tree_node); } + // Start detecting spammers once we have less than 20% + // of async space left (which is less than 10% of total + // buffer size). + // + // (This will short-circuit, so `low_oneway_space` is + // only called when necessary.) + let oneway_spam_detected = + is_oneway && new_oneway_space < self.size / 10 && self.low_oneway_space(pid); + Ok((found_off, oneway_spam_detected)) } -- cgit v1.2.3